It is known to use baskets made from nets for pisciculture (see for example JP 2002 045084 or WO 96 13973). The net made of plastic is generally knotted at the cross-over points, generally has a rope diameter of approximately 2-8 mm, and must have relatively small mesh openings of approximately 10-30 mm. Due to the correspondingly large “material surface” there is a risk that animals and plants such as e.g. algae, seaweed, moss, mussels, etc. will become caught, held or will accumulate in these meshes, and this will have a negative impact upon the penetrability of the net, and so upon the pisciculture since the inflow of nutrients and the supply of oxygen thus takes place unsatisfactorily.
EP-B-0 979 329 discloses a high-strength wire netting for protection against falling rocks or for securing a surface layer of earth which is woven from high-strength steel wires bent in spiral coils and has a three-dimensional structure. The wires bent in spirals have a gradient angle and a length between two bends which determine the shape and size of the meshes of the wire netting.
The wire material is produced by a method in which the wire is fed to a mandrel at the defined gradient angle and is bent in the defined length around the mandrel by for example over approximately 180°, the wire having to be fed a number of times in its longitudinal axis to the mandrel about the defined length and having to be bent respectively around the mandrel. The method and the device required for this purpose is relatively complicated and correspondingly expensive.